1ZHA

A. aeolicus KDO8PS R106G mutant in complex with PEP and R5P


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.74 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

The Catalytic and Conformational Cycle of Aquifex aeolicus KDO8P Synthase: Role of the L7 Loop.

Xu, X.Kona, F.Wang, J.Lu, J.Stemmler, T.Gatti, D.L.

(2005) Biochemistry 44: 12434-12444

  • DOI: 10.1021/bi051095q
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • KDO8P synthase catalyzes the condensation of arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) to form the 8-carbon sugar KDO8P and inorganic phosphate (P(i)). The X-ray structure of the wild-type enzyme shows that when both PEP and A5P bind, ...

    KDO8P synthase catalyzes the condensation of arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) to form the 8-carbon sugar KDO8P and inorganic phosphate (P(i)). The X-ray structure of the wild-type enzyme shows that when both PEP and A5P bind, the active site becomes isolated from the environment due to a conformational change of the L7 loop. The structures of the R106G mutant, without substrates, and with PEP and PEP plus A5P bound, were determined and reveal that in R106G closure of the L7 loop is impaired. The structural perturbations originating from the loss of the Arg(106) side chain point to a role of the L2 loop in stabilizing the closed conformation of the L7 loop. Despite the increased exposure of the R106G active site, no abnormal reaction of PEP with water was observed, ruling out the hypothesis that the primary function of the L7 loop is to shield the active site from bulk solvent during the condensation reaction. However, the R106G enzyme displays several kinetic abnormalities on both the substrate side (smaller K(m)(PEP), larger K(i)(A5P) and K(m)(A5P)) and the product side (smaller K(i)(Pi) and K(i)(KDO8P)) of the reaction. As a consequence, the mutant enzyme is less severely inhibited by A5P and more severely inhibited by P(i) and KDO8P. Simulations of the flux of KDO8P synthesis under metabolic steady-state conditions (constant concentration of reactants and products over time) suggest that in vivo R106G is expected to perform optimally in a narrower range of substrate and product concentrations than the wild-type enzyme.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
2-dehydro-3-deoxyphosphooctonate aldolase
A, B
267Aquifex aeolicus (strain VF5)Mutation(s): 1 
Gene Names: kdsA
EC: 2.5.1.55
Find proteins for O66496 (Aquifex aeolicus (strain VF5))
Go to UniProtKB:  O66496
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
R5P
Query on R5P

Download SDF File 
Download CCD File 
A
RIBOSE-5-PHOSPHATE
C5 H11 O8 P
PPQRONHOSHZGFQ-LMVFSUKVSA-N
 Ligand Interaction
PEP
Query on PEP

Download SDF File 
Download CCD File 
A, B
PHOSPHOENOLPYRUVATE
C3 H5 O6 P
DTBNBXWJWCWCIK-UHFFFAOYSA-N
 Ligand Interaction
CD
Query on CD

Download SDF File 
Download CCD File 
A, B
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PEPKd: 40 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.74 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.207 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 84.726α = 90.00
b = 84.726β = 90.00
c = 160.433γ = 120.00
Software Package:
Software NamePurpose
CNSphasing
CrystalCleardata reduction
d*TREKdata reduction
CrystalCleardata collection
CNSrefinement
d*TREKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-09-27
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model
  • Version 1.4: 2017-10-11
    Type: Refinement description